A Circulating Biomarker Risk-Prediction Model Correlates with CHADS-2 Risk Score in Chronic Atrial Fibrillation.

BACKGROUND

Inflammation and oxidative stress have been linked to the origin and persistence of atrial fibrillation (AF). CHADS-2 scoring system is a risk stratification schema well validated in prognostication of stroke in AF. We evaluated the association of markers of oxidative stress and inflammation with CHADS-2 scores in chronic AF patients.

METHODS

CHADS-2 scores were calculated for 64 subjects with chronic AF. Serum markers of inflammation [C-reactive protein (hs-CRP), interleukin-6 (IL-6), interleukin 1β (IL-1β), tumor necrosis factor-α (TNF-α)] and of oxidative stress [Derivatives of reactive oxygen metabolites (DROMs) and isoprostanes (IsoPs)] were measured.

RESULTS

Twenty subjects were categorized as 0 (no risk), 24 as 1 (intermediate risk) and 20 as 2 (severe risk) based on their CHADS-2 scores. High sensitivity-CRP (CHADS-2 0=40.0%, 1=70.0%, 2=90.0%; p=0.003) and DROMs (CHADS-2 0=45%, 1=78%, 2=80%; p=0.04) were positively associated with the CHADS-2 risk score. Subjects with intermediate to severe CHADS-2 risk retained significant associations with abnormal hs-CRP (OR: 5.3, 95%CI: 1.1-25.0) and DROMs (adjusted OR: 6.7, 95%CI: 1.2-38.8) after adjusting for gender and hypertension. In a multiple logistic interaction model, there was no significant interaction between hs-CRP and DROMs in their association with CHADS-2 risk categories (p=0.64). A biomarker risk-model, combining hs-CRP and DROMs, correlated well with the CHADS-2 risk categories (r= 0.49, p<0.001).

CONCLUSIONS

A biomarker risk-model using a combination of hs-CRP and DROMs correlates well with CHADS-2 risk scores in chronic AF. Either or both of these markers may add predictive power to future stroke risk prediction models.